Best friends David Peck and Doug Schwartz of Concord weren’t expecting a large crowd when they created their own version of Gutenberg! The Musical! by Anthony King and Scott Brown, but they very well may get one when they perform it at the Capitol Center for the Arts this Friday.

The play was originally supposed to happen in a backyard with 10, 15 audience members tops. They started rehearsing because Peck needed to put on a performance as his last singing lesson assignment from his teacher, Tony Bonjorno.

“For the past 27 years, I worked in the court system for the State of New Hampshire,” Peck said. “One of the things I’ve always kind of wanted to do was take voice lessons and learn how to sing. … But I was working a lot of hours and didn’t have time to devote to practicing. When I went to part-time … I said, if I’m ever going to do it, it’s now.”

He started at the end of 2013, right around when he turned 60. He mulled over performance possibilities one night while eating dinner with Schwartz, whom he’d met as a freshman at Colby College, and his wife, Colleen Schwartz. Should he go for karaoke? Showtunes? A recital?

“Then Colleen said, ‘The two of you could do something together,’” said Peck.

Doug Schwartz boasts far more theater experience than Peck, but they’d jammed out and sung in chorales together. He knew Peck’s potential.

“It wasn’t that he needed to learn how to sing. He needed to develop confidence to feel he could sing well enough to sing in public. I knew he could sing. We’ve been singing together for decades,” Doug Schwartz said.

Both liked the idea of collaborating, but neither guy knew any two-man musicals. So Colleen Schwartz searched online and found Gutenberg! The Musical! They ordered the original CD and fell in love — the songs were silly but good, and so was the play. Plus, Schwartz knew how to pull off silly, having directed the Community Players of Concord’s take of Spamalot a couple years ago.

The musical is a play-within-a-play that was part of the 2005 and 2006 New York Musical Theatre Festival, opening off-Broadway later that December. It follows two playwrights, Bud Davenport and Doug Simon, who’ve written a musical about printing press inventor Johannes Gutenberg.

They need to find big backers, and because they don’t yet have the budget for a full cast and orchestra, they play all the characters themselves with the help of baseball caps with names on top.

The musical they’ve come up with is Gutenberg! The Musical!, which is set in a medieval German town, Schlimer, where nobody except Gutenberg and the evil monk can read. His goal in turning his wine press into a printing press is to save the townspeople from their own ignorance, and he does so with help from his beautiful assistant, Helvetica. But Monk, who worships Satan, has his own plans to keep ignorance alive so he can control townspeople by making up the Bible’s content. He hatches a plan to destroy the press with a No. 2 pencil.

“We initially thought maybe we’d perform two to three songs and do this as a mini-recital. … But as we started working on it, it became clear nobody would understand these songs unless we have the surrounding dialogue,” Peck said.

Soon they were learning the entire musical. Community Players of Concord member Bob Pearson sat in on a rehearsal and told them to aim higher, so they took the full production to the Players’ Studio in Concord, open to only friends and members, for a performance last July. Folding chairs came out of storage and sat in front of a very minimalist warehouse stage. There were no sets, no fancy costumes, only hats. Laughter filled the studio within the first few lines.

“We had no idea what would happen, but 80 people showed up, and they loved it. I had no idea how much people would like it, but we had more fun than I could have imagined in my wildest dreams,” Doug Schwartz said.

The Players’ board asked them to perform it again in February, this time as a fundraiser.